Hypertrophy of the Denervated Hemidiaphragm

Abstract
The phenomenon of hypertrophy of the hemidiaphragm following denervation was found to occur in the mouse, rabbit and in the right hemidiaphragm of the rat. The peak of the hypertrophy occurred between 5 and 8 days in the mouse, at which time increases of 24–57% in wet weight of the hemidiaphragm were observed. In the rabbit the maximum hypertrophy observed was 29.5% at 10 days after denervation. The response of the right hemidiaphragm to denervation was quantitatively very similar to the response of the left hemidiaphragm in the rat. A slight increase in relative amount of water was observed in the hemidiaphragms of both the mouse and rat which does not account for the observed increases in wet weight.